Text Viewports have coordinate systems having units of Rows and Columns,
with the coordinate origin being the top left-hand corner of the screen or
Viewport. For consistency between Text and Graphics Viewports, these
coordinates are expressed as floating point numbers. Thus, for a typical
terminal, Rows (Y) may be expressed in the range 1.0 to 24.0 and Columns (X)
may be expressed in the range 1.0 to 80.0. Each Viewport is surrounded by a
border, which lies outside of the Viewport itself. Thus, for a terminal having
24 rows (Lines) of 80 characters (Columns), the largest Viewport having a
visible border is defined as having its origin at (2.0,2.0) and a size of
(78.0,22.0)